Tension element position sensors of this type are known in the marketplace and are being offered in various embodiments:                on the one hand side, they differ through the tension element being used:        
For a typically multi-strand thin steel cable configured as a tension element, the cable is wound in one layer adjacent to itself on the winding drum which simplifies processing in that each rotation corresponds to the same pullout length. A disadvantage is the limited loading of the cable and a pullout length that is a function of width and diameter of the cable drum.
When a band is configured as a tension element, the band is wound in a radial plane in plural layers on top of one another so that a rotation corresponds to different pullout lengths depending whether the location is further towards the core or further towards the outside of the spiral.                The functional components of the winding drum on the one hand side and the spiral spring preloading it in windup direction can be different:        
Arranged in axial direction behind one another, assembly is simpler and less dangerous, however, it yields a relatively large axial length.
An axially short housing is obtainable when the spiral spring is arranged directly in the interior of the winding drum which, this, however makes assembly more difficult and requires a sufficiently large free space at this location. When the cable is only wound up in one layer, this is typically the case.                For angle sensors, so far mechanical multi-turn potentiometer or optical encoders were used. As an additional alternative now in particular magnetic field direction sensitive angle sensors have been added in which a magnet with its pole axis transversal to the rotation axis of the winding drum is coupled with the winding drum and the rotation of the magnetic field is detected, wherein additional measures have to be performed to provide multi-turn scanning.        